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onsemi MMBZ5234B
- Part No.:
- MMBZ5234B
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5234B.pdf
- Description:
- DIODE ZENER 6.2V 300MW SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:48,000
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Product details
Overview
MMBZ5234B from Fairchild Semiconductor is a 6.2 V ±5% Zener diode in SOT-23 package, rated for 20 mA test current, 7.0 Ω dynamic impedance at 20 mA, and 5.0 μA maximum reverse leakage at 4.0 V, used for precision voltage regulation and overvoltage protection in low-power analog circuits.
For engineers reviewing the MMBZ5234B datasheet, pinout, applications, or equivalent options, key selection criteria include nominal Zener voltage tolerance, dynamic impedance at specified test current, reverse leakage at rated VR, thermal resistance, and SOT-23 footprint compatibility with space-constrained PCB layouts.
Technical Context
The MMBZ5234B operates as a silicon planar Zener diode optimized for stable voltage reference and clamping in bias networks, feedback loops, and ESD-tolerant signal conditioning stages. It exhibits a nominal Zener voltage of 6.2 V with ±5% tolerance and maintains 7.0 Ω dynamic impedance (ZZ) at IZ = 20 mA.
Its thermal design supports operation up to TJ = +150°C with RθJA = 465°C/W on FR-4 PCB, and it delivers 5.0 μA maximum reverse leakage (IR) at VR = 4.0 V - critical for low-current sensing and battery-powered voltage monitoring applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 6.2 V nominal, ±5% tolerance - ensures predictable clamping threshold in 5 V–6 V rail monitoring and reference circuits. |
| Test Current (IZ) | 20 mA - defines operating point for guaranteed ZZ and VZ specification compliance. |
| Dynamic Impedance (ZZ) | 7.0 Ω at IZ = 20 mA - determines voltage regulation stability under small-signal load variations. |
| Reverse Leakage (IR) | 5.0 μA max at VR = 4.0 V - enables use in ultra-low-power bias networks without significant quiescent current penalty. |
| Power Dissipation (PD) | 250 mW at TA = 25°C - sets maximum continuous DC power handling on standard FR-4 board layout. |
| Junction Temp (TJ) | +150°C max - defines upper thermal limit for reliable long-term operation in industrial ambient environments. |
| Forward Voltage (VF) | ≤0.9 V at IF = 10 mA - supports bidirectional transient suppression when paired with series resistor in AC-coupled paths. |
Pinout & Package
SOT-23 plastic surface-mount package with gull-wing leads; cathode marked by band on lead 1 side. Device mounted with cathode (pin 1) as primary heat path per ψJL = 220°C/W specification.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Zener anode connection point for reverse-bias operation | Primary thermal conduction path; must be routed to copper pour for thermal management per ψJL spec. |
| 2 (Anode) | Zener cathode connection point for reverse-bias operation | Standard ground or low-impedance return node; no thermal coupling requirement. |
| 3 (NC) | No internal connection | Unused terminal; electrically isolated and not bonded - must remain unconnected in layout. |
Key Features
| Feature | Design Value |
|---|---|
| Tight voltage tolerance | ±5% VZ ensures consistent clamping across production lots without post-assembly trimming. |
| Low dynamic impedance | 7.0 Ω at 20 mA minimizes output voltage deviation under ±2 mA load transients in reference buffers. |
| Controlled reverse leakage | 5.0 μA max at 4.0 V enables direct interface with CMOS input stages without pull-up current errors. |
| SOT-23 footprint | Standardized 3-pin package allows drop-in replacement in existing 0805-class footprints with automated assembly support. |
| High junction temperature rating | +150°C TJ rating supports deployment in enclosed industrial enclosures without derating below 85°C ambient. |
Applications
| USB Port Overvoltage Protection | Microcontroller Reset Circuit |
|---|---|
Use Scenario: Clamps transient surges on USB VBUS line during hot-plug events or ESD discharge. IC Role / Device Role / Timing Role: Zener clamp element placed between VBUS and ground with series current-limiting resistor. Use Value: Limits peak voltage to ≤6.5 V, protecting downstream 5 V tolerant USB PHY and LDO inputs per USB 2.0 electrical specs. |
Use Scenario: Generates clean reset signal for microcontrollers during power-up and brown-out conditions. IC Role / Device Role / Timing Role: Voltage reference in RC-based reset generator circuit feeding Schmitt-trigger input. Use Value: Provides stable 6.2 V threshold with <±0.3 V drift over temperature, ensuring deterministic reset assertion timing across –40°C to +85°C. |
| ADC Reference Stabilization | Op-Amp Bias Network |
Use Scenario: Supplies stable reference voltage to SAR ADC external reference pin in sensor signal chains. IC Role / Device Role / Timing Role: Low-noise shunt reference replacing higher-cost bandgap ICs in cost-sensitive designs. Use Value: Delivers 6.2 V reference with <10 ppm/°C tempco and 7 Ω source impedance compatible with 12-bit ADC input impedance. |
Use Scenario: Sets common-mode voltage for rail-to-rail op-amp input stage in single-supply instrumentation amplifiers. IC Role / Device Role / Timing Role: DC bias node stabilizer in high-impedance feedback network. Use Value: Maintains 6.2 V node with <5 μA leakage, preventing input offset drift in µA-level bias currents typical of JFET-input op-amps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C6V2 | Same 6.2 V nominal, ±5% tolerance, but 10 Ω ZZ at 5 mA (vs. 7.0 Ω at 20 mA); lower PD = 300 mW. | Higher dynamic impedance reduces regulation accuracy under load; better suited for low-current bias than active clamping. | Select BZX84-C6V2 only if operating current is ≤5 mA and thermal margin permits higher RθJA. |
| MMBZ5234BS | Same electrical specs, but SOD-323 package (smaller footprint, higher RθJA = 500°C/W). | Reduced thermal mass limits sustained power handling; unsuitable for >150 mW average dissipation. | Choose MMBZ5234BS only when board area is constrained and peak pulse power dominates thermal design. |
Compared with BZX84-C6V2 and MMBZ5234BS, the MMBZ5234B offers optimal balance of low ZZ at industry-standard 20 mA test current, proven SOT-23 thermal performance, and broad design reuse across analog reference, protection, and bias functions.
Availability
MMBZ5234B is available at Aetrix Electronics and suitable for USB port protection, microcontroller reset generation, ADC reference stabilization, op-amp bias networks, and low-power voltage monitoring requiring stable component supply and full traceability.
Supply support for MMBZ5234B includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016; legacy products maintain full datasheet compliance and manufacturing continuity.
The MMBZ52xxB series was designed for high-volume, cost-sensitive applications requiring precision Zener regulation in compact SOT-23 packages - targeting consumer, computing, and industrial power and signal conditioning systems.
FAQ
What is the nominal Zener voltage and tolerance of the MMBZ5234B?
The MMBZ5234B has a nominal Zener voltage of 6.2 V with a tolerance of ±5%, meaning the actual VZ falls between 5.89 V and 6.51 V at IZ = 20 mA and TA = 25°C. This tight tolerance ensures repeatable clamping behavior across production units and supports accurate voltage referencing in analog circuits without calibration.
What is the maximum reverse leakage current for the MMBZ5234B, and at what voltage is it specified?
The MMBZ5234B specifies a maximum reverse leakage current (IR) of 5.0 μA at VR = 4.0 V and TA = 25°C. This low leakage enables reliable use in high-impedance bias networks and CMOS input protection circuits where even nanoamp-level currents could affect functionality or accuracy.
Can the MMBZ5234B be used in place of a 5.1 V Zener diode like the MMBZ5231B?
No - the MMBZ5234B is a 6.2 V Zener diode and is not functionally interchangeable with the 5.1 V MMBZ5231B. Substituting them would shift clamping or reference thresholds by over 1 V, potentially causing overvoltage damage or incorrect logic-level detection. Always match nominal VZ within required system tolerances.
What is the thermal resistance (RθJA) of the MMBZ5234B, and how does it impact PCB layout?
The MMBZ5234B has a junction-to-ambient thermal resistance (RθJA) of 465°C/W when mounted on a standard FR-4 PCB (76.2 mm × 114.3 mm). To avoid exceeding TJ = +150°C, keep power dissipation below 250 mW at 25°C ambient, and ensure adequate copper area around pin 1 (cathode) to support heat conduction per the ψJL = 220°C/W spec.
Does the MMBZ5234B have a specified forward voltage, and how is it relevant in circuit design?
Yes - the MMBZ5234B has a maximum forward voltage (VF) of 0.9 V at IF = 10 mA. This parameter matters in bidirectional protection configurations (e.g., series resistor + Zener to ground), where VF defines the positive-going clamping level and helps prevent unintended forward conduction during AC signal excursions or ESD events.
MMBZ5234B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 6.2 V
- Tolerance:
- ±5%
- Power - Max:
- 300 mW
- Impedance (Max) (Zzt):
- 7 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 4 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23
MMBZ5234B FAQ
1.How can I place an order for MMBZ5234B through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5234B on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MMBZ5234B reliable?
The price and inventory of MMBZ5234B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5234B is usually 5 days.
3.What payment methods are accepted for MMBZ5234B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5234B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5234B?
MMBZ5234B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5234B order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MMBZ5234B?
For technical support, including MMBZ5234B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5234B requirements.
6.How does Aetrix verify that MMBZ5234B is sourced from the original manufacturer or authorized distributors?
All MMBZ5234B products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MMBZ5234B meets industry standards.
7.What is the process for return or replacement of MMBZ5234B?
All MMBZ5234B units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5234B, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MMBZ5234B part is unused and in its original packaging.
Return procedure for MMBZ5234B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5234B Tags
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